It is well known in aircraft to have strips of electrical lights mounted at floor level to guide passengers to the emergency exit doors of the aircraft. The strips of electric lights are powered by an emergency battery. Such systems work well, but they have some problems.
One problem is that they need regular servicing. The electrics needs checking periodically and bulbs need replacing. Maintenance of the floor-level emergency exit lights adds significantly to the cost of maintaining an aircraft. Also the power drain caused by running the lights adds to fuel costs.
A further problem is that if the emergency battery fails there is no guide lighting for the passengers leading them to the exits.
Another problem is that in the event of a crash the electrical wires connecting some or all of the floor level emergency lights can be broken, again meaning that some or all of the floor-level emergency lights are inoperative at just the time that they are most needed.
It is an aim of one embodiment of the present invention to alleviate at least some of these problems.